Earlier this month the Tooting MP told the Guardian newspaper: “One of my criticisms of Tony Blair was when he called the four MPs of Islamic faith into No 10 and sat us round the table and said – to Mohammad Sarwar, Khalid Mahmood, Shahid Malik and myself – it was our responsibility,”

“I said: ‘No, it’s not. Why have you called us in? I don’t blame you for the Ku Klux Klan. Why are you blaming me for the four bombers on 7/7?’ Which is why, after he called us in, and there were lots of cameras outside waiting to speak to us, my three colleagues spoke to the cameras and I walked away. This is a problem that is a mainstream problem for us all.”

However Khan’s account has been challenged by Mahmood and Malik who, having consulted with Mr Sarwar, have written to the paper describing themselves as “extremely troubled by Khan’s evidently self-serving revisionism.”

The pair say that contrary to the account relayed by Mr Khan, “our Downing Street discussions in fact ended with a unanimous agreement on the need for unity in the fight against terror and the crucial role for Muslims.”

They add: “To misrepresent the words of a British prime minister and to mischaracterise a significant meeting in the wake of the tragic loss of 52 lives a week earlier is frankly beyond the pale, and we write today not to defend Blair but to defend the truth.

“Khan’s depiction of his bravado is almost comical, and if the events of 7/7 were not so grave, it would be unworthy of response. But this was a profoundly grave episode in our history, which necessitates challenging those who would seek to exploit it for personal gain.”

“While we agree with Khan that it would be great to see a Muslim mayor for London – as indeed it would to see a black mayor or woman mayor – above all it would be good to see a mayor who could truly command the trust of Londoners irrespective of their colour, creed, race, or gender.”

Mr Khan’s campaign has been asked to respond to the letter and its claims.